RC cars, or radio-controlled cars, are model cars driven from a distance using a radio control system. Building, modifying and driving RC cars is a very popular hobby. They range from simple “stop and go” toy cars to competitive racing models that feature the complexity and adjustability of their full-size counterparts. RC cars date to the 1940s, when small nitro methane-powered engines entered the market. However, at this time, there was insufficient technology to control an engine-powered model car other than on a tether. In the 1960s, the first miniaturized solid state radio control systems became available, which allowed a model car to have servo-controlled steering, throttle, and brake functionality that could be remotely controlled from a radio-control transmitter unit. This allowed model cars to be able to run on a racetrack with the ability for precise control in a similar manner as with a full-sized vehicle. By the early 1970s, several small firms in the U.S. were selling RC car kits.

RC cars are categorized as either “toy” or “hobby” grade and are powered by various sources. Electric cars are powered by small, powerful electric motors and rechargeable nickel-cadmium, nickel metal hydride, or lithium polymer cells. Most fuel-powered models use glow plug engines, small internal combustion engines fueled by a special mixture of nitromethane, methanol, and oil (in most cases a blend of castor oil and synthetic oil). These are referred to as "nitro" cars. Recently, exceptionally large models have been introduced that are powered by small gasoline engines, which use a mix of oil and gasoline. Electric cars are generally considered easier for the novice to work with compared to fuel-driven models, but can be equally as complex at the higher budget and skill levels. Both electric and nitro RC cars are available for on-road and off-road. Electric and nitro cars have come a long way in terms of power. Electric cars have gone from non-rebuildable brushed motors and ni-cad batteries to brushless motors and LiPo. Nitro cars have gone from small engines to huge .32 engines that are used in big monster trucks.

Toy-Grade RC Cars
The term "toy-grade" in regards to radio control cars is used to describe vehicles of the pre-assembled type generally found in discount stores and consumer electronics stores. Some toy-grade RC cars may also be found in hobby shops in an attempt to appeal to young users. Generally speaking, a toy RC car is a child’s plaything.

Hobby-Grade RC Cars
In recent years, hobby-grade "ready-to-run" (or RTR) model cars have become more popular and are available from every major manufacturer of radio-controlled cars. Vehicles of this type need little or no final assembly. In most cases, the bodies are shipped painted and trimmed, requiring little work from the owner before they can be used (other than purchasing and installing batteries). A number of cars and trucks are presently available only in ready-to-run form. The growing popularity of the RTR vehicle has prompted manufacturers to introduce kit versions of their RTR cars that include factory upgrades but have no radio gear installed and often no motor or speed controller.